The present invention is generally directed to a method for the rapid screening of chemicals, catalysts, reactants, process conditions and the like. More specifically, the present invention is directed to the use of Incremental Flow Reactor (IFR) methodology on large arrays of miniaturized reactor vessels to identify potential reactants and catalyst systems for the bulk chemical industry.
Combinatorial chemistry is a popular research tool among scientists in many different fields. High throughput and combinatorial screening for biological activity have been prevalent in the pharmaceutical industry for nearly twenty years. More recently, high throughput and combinatorial screening for improved catalysts for the bulk chemical industries have enjoyed increasing popularity. Despite their popularity, development of high throughput and combinatorial screening for production scale reactions has been lagging. This has been due in large part to the difficulty in emulating the production-scale reactions at the micro-scale level, which is necessary for this type of work. In particular, special problems can arise in reactions that are significantly dependent on flow rate or configuration.
To date, most combinatorial work has focused on xe2x80x9csolid phasexe2x80x9d reactions. It is known that a wide variety of organic reactions can be carried out on substrates immobilized on resins. However, a substantial number of production scale reactions are xe2x80x9cliquid phasexe2x80x9d or xe2x80x9cmixed phasexe2x80x9d and are carried out in continuous flow reactor systems.
Early efforts in high throughput screening of solutions have focused on catalyst screening. Before the application of the high throughput and combinatorial approaches, catalyst testing was traditionally accomplished in bench scale or larger pilot plants in which the feed to a continuous flow reactor was contacted with a catalyst under near steady state reaction conditions. However, rapid and combinatorial screening of reactants, catalysts, and associated process conditions requires that a large number of reactions or catalytic systems be tested simultaneously. In certain applications, screening-level data can be generated by using miniaturized batch reactors in conjunction with liquid-handling robots that aliquot the appropriate catalysts and reactants to each vial or reaction well. In other applications, however, batch reactions do not behave in the same fashion as continuous flow reactions, and could provide misleading results if the goal of screening is to identify reactants or catalyst systems that will be implemented in production-scale continuous flow reactors.
As the demand for bulk chemicals continues to grow, new and improved methods of producing more product with existing resources are needed to supply the marketplace. Unfortunately, the identification of additional effective reactants and catalyst systems for these processes continues to elude industry. There, thus, remains a need for new and improved methods for rapidly screening potential reactants, catalysts, and associated process conditions.
The present invention is directed to the use of IFR methodology on large arrays of miniaturized reactor vessels to produce chemical reactions that emulate those carried out in production-scale, continuous flow or continuous stirred tank reactors. With IFR, high throughput combinatorial screening of chemicals, catalysts, reactants, and associated process conditions is achieved. The use of liquid and solid handling robotic equipment to implement the IFR on numerous reactor arrays is also described.
In one embodiment the present invention is a method for producing multiple chemical reactions and catalytic systems in the reaction of at least one monohydroxyaromatic compound and at least one aldehyde or ketone to produce at least one bisphenol in batch reactors emulating the conditions of continuous reactors by incremental flow, comprising the steps of: providing a large array of reactor vessels and reactants; loading each reactor vessel with at least one reactant; and allowing the reactions to proceed for a predetermined time interval. A volume increment is withdrawn from each of the reactor vessels and a volume increment of at least one reactant is added to each reactor vessel in the array. The steps of volume increment withdrawal and addition are repeated after successive time intervals until the reactions reach a substantially steady state.
In alternative embodiments, the volume increment withdrawal can take place before, after, or contemporaneously with the volume increment addition.